Add sriracha sauce and sesame oil in a pot an let it bubble, add the onions and tomatoes and cook for approx. 3 mnts while stirring occasionally. Add ginger garlic and cook for 2 more minutes until soft. Now add water and bring it to a boil. Transfer this into a blender and blend into a smooth mixture. Return it to the pot and add the chicken stock and let it simmer until it boils. Now add soy sauce and vinegar and cook for 5 to 10 more minutes on low heat.